Predicting Stroke Risk after TIA
Johnston SC, et al. Lancet. 2007;369:283-292.
Stroke remains the third leading cause of death in America. Risk of stroke after TIA is greatly magnified, such that as many as 20% will suffer a stroke within 90 days, disproportionately occurring within the first 48 hours post-TIA. Scoring systems to enhance prediction of stroke after TIA have been devised and validated, and include the ABCD score and the California score. These scores had different boundaries (the ABCD score predicted 7 day risk; the California score looked at 90 day risk), and because of questions about generalizability (the ABCD was validated on Greek and British populations, vs the California Score which was developed from an American cohort), it would be desirable to evolve a single score capturing the best aspects of both the ABCD and California scoring system.
Based on logistic regression, the authors derived a "unified ABCD" score and validated it upon a large population of individuals (n = 4,809) from American and British populations. The new scale, which they term the ABCD2, is so-named because it predicts risk in the 2 days post-TIA. Components of the ABCD2 include age, diabetes, blood pressure, duration of TIA, speech impairment, and focal weakness. The new scale predicts high risk patients in the first 48 hours better than either of the component scores from which it was derived. The authors offer this scale as a new "standard of care" model for identifying highest risk TIA patients who may benefit from more intensive investigation and treatment.
Which is the Better Study in Acute Stroke: CT or MRI?
Chalela JA, et al. Lancet. 2007;369:293-298.
Common wisdom suggests that for acute stroke, MRI is preferred to CT. Sometimes, however, patients who present with neurologic syndromes may suffer disorders other than/in addition to stroke. Hence, clinicians would prefer to know which imaging modality provides best information about stroke (ischemic and hemorrhagic), as well as other cerebrovascular maladies.
It is already recognized that CT is less valuable for detecting ischemic stroke than ruling out hemorrhagic stroke. Yet, there has been little comparison to determine whether CT or MRI is actually superior to detect CNS hemorrhage.
In a prospective blind comparison of CT and MRI in patients presenting with suspected acute stroke, MRI was significantly more sensitive for both ischemic and hemorrhagic stroke detection. When assessed comparatively relative to the final clinical diagnosis, the sensitivity of MRI was substantially greater than CT (83% vs 26%). Unless cost or availability precludes its use, MRI should be the preferred study in patients presenting with symptoms suggesting acute stroke.
Comparison of a DPP-4 and TZD for Monotherapy in Type 2 Diabetes
Rosenstock J, et al Diabetes Care. 2007;30(2):217-223.
Glucagon-Like Peptide-1 (GLP) is one of a family of agents known as incretins (FYI, correctly pronounced in-KREE-tins, since your author has heard it repeatedly mispronounced "IN-creh-tins" at professional meetings of late). Incretins have numerous favorable physiologic effects in patients with type 2 diabetes (DM2), including enhanced glucose-dependent insulin secretion, activation of insulin biosynthesis and gene transcription, suppression of glucagon, slowed gastric emptying, induction of satiety, and inhibition of beta cell apoptosis. Until very recently, we have not been able to capitalize upon these physiologic attributes because the actions of GLP are very short lived. DPP4 inhibitors block the enzyme that degrades GLP, resulting in a prolonged GLP effect. Sitagliptin (Januvia) is the only currently approved DDP4 inhibitor, but others are pending FDA approval.
The potency of the DPP4 inhibitor vildagliptin (VIL) was compared in a double-blind fashion with rosiglitazone (Avandia) in type 2 diabetics A population of newly diagnosed diabetics (n = 786) were randomized to VIL 50 mg b.i.d. vs rosiglitazone 8 mg qd and followed for 6 months. The primary outcome was changed from baseline A1C (baseline = 8.7).
Both agents were similar in mean reduction of A1C at 24 weeks (1.1-1.3%), proving statistical noninferiority of vildagliptin to rosiglitazone. Additionally, amongst persons with higher baseline A1C (eg, > 9.0%), pharmacotherapy impact was correspondingly larger (A1C decrease 1.8%).
Because they are not associated with weight gain, and show similar potency to agents popularly used to treat DM2, the availability of this new class of oral agents is welcome.
Hypertension Treatment in "Real Life": How are We Doing?
Petrella RJ, et al. Clin Hypertension. 2007;9(1):28-35.
Data in the United States from the NHANES (National Health and Nutrition Examination Survey) have shown that rates of awareness, treatment, and control of blood pressure remain remarkably suboptimal, despite over three decades of periodic NHANES data reporting and diversification of therapeutic choices. Because most hypertension is treated in the primary care sector, specifically Family Medicine, a perspective on prevalence, treatment, and control in this population is valuable.
The burden of hypertension (HTN) in Canada appears similar to the USA. Petrella utilized a database of 150,000 patients from family practice clinics in Ontario to derive prevalence, treatment, and control assessments. HTN was defined as > 140/90 for the general population, > 130/80 for diabetics, and > 160 systolic for Isolated Systolic Hypertension.
Based upon these definitions, the majority of persons with hypertension were untreated (68.6%), and only 15.8% had blood pressure treated and controlled. When viewed in concert with US population data, the challenge of blood pressure control in North America remains daunting.
Can We Prevent Recurrences of Diabetic Foot Ulcers?
Lavery LA, et al Diabetes Care. 2007;30(1):14-20.
Diabetes remains the number one cause of atraumatic limb loss, the majority of which is secondary to diabetic neuropathy, subsequent infection, and tissue loss. Standard management for diabetic patients, including those with a history of foot ulcers, includes periodic clinician examination, education on maintenance of foot skin integrity, examination, prevention of injury, and daily foot self-inspection.
Lavery, et al assessed the comparative efficacy of standard management with what they termed Structured Foot Examination (SFM) and Enhanced Therapy (ENH) in a population of diabetics who would well be considered high-risk because they had already sustained a diabetic foot ulcer. SFM included standard management plus training to perform a twice daily mirror-assisted foot examination seeking redness, discoloration, swelling, and local warmth. Results of the SFM were recorded in a logbook. ENH consisted of standard management plus personal instruction on use of a digital infrared thermometer. Foot temperature was measured with the digital infrared thermometer at six sites, and recorded in a logbook. Subjects in each group were advised to make clinician contact for any changes detected.
The primary outcome of the trial was foot ulceration during 15 months of followup. ENH was significantly superior to both standard management and SFM. Overall, there was a four-fold decrease in risk of developing a foot ulcer in the ENH group compared to other groups.
Once a patient has suffered a diabetic foot ulcer, recurrences may be as common as 25% annually or more. A patient-administered temperature monitoring device may substantially reduce this risk.
Contact Sensitizers Are Surprisingly Common in Chronic Urticaria
Guerra L, et al J Am Acad Dermatol. 2007;56:88-90.
Up to half of all persons who suffer chronic urticaria (URT) never learn the causative factor. Recently, dermatologists have noted that contact sensitizers are culprits in URT even though patients may NOT evidence irritation at the site of contact in daily life. To better ascertain the percentage of persons who might be suffering sensitivity to contact allergens, Guerra et al performed evaluations on 121 patients with URT who had already undergone "traditional" diagnostic tests including ESR, blood chemistry, urinalysis, food scratch testing, total IgE levels (as well as IgE specific to Anisakis and Echinococcus), HIV and hepatitis testing, thyroid testing, ANA, stool parasite analysis, Helicobacter testing, autologous serum skin testing, CXR, hereditary angioedema screening, urine electrophoresis, lymphocyte subpopulation analysis, and extractable nuclear antigens (Whew!!). In addition, study subjects underwent an Italian made specialty Patch Testing system which includes metals, chemicals, cleaning agents, and cosmetics.
Fifty subjects (41%) had positive tests using the novel patch testing panel. None of these individuals had manifested signs of contact dermatitis at the actual sight of exposure in day-to-day activity. In addition to a positive patch test result, application of the culprit allergen to the skin resulted in a worsening of urticaria in approximately half of them. Of the 50 patch test positive patients, everyone who practiced avoidance of the demonstrated allergen enjoyed remission of URT!! Contact sensitization is an underappreciated etiology of URT, but specialized testing panels may be required to detect it and intervene appropriately.
Predicting Stroke Risk after TIA; Which is the Better Study in Acute Stroke: CT or MRI?; Comparison of a DPP-4 and TZD for Monotherapy in Type 2 Diabetes; Hypertension Treatment in "Real Life": How are We Doing?; Can We Prevent Recurrences of Diabetic Foot Ulcers?; Contact Sensitizers Are Surprisingly Common in Chronic UrticariaYou have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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